Cosmologists have shown that it’s theoretically possible for a contracting universe to bounce and expand. The new work resuscitates an old idea that directly challenges the Big Bang theory of cosmic origins.

It weighs as much as 780 million suns and helped to cast off the cosmic Dark Ages. But now that astronomers have found the earliest known black hole, they wonder: How could this giant have grown so big, so fast?

Astronomers thought that all Type Ia supernovas shine with the same brightness, making them incredibly useful cosmic yardsticks. But uncertainty over what causes these explosions has led researchers to reconsider their assumptions.